Lim IGARSS2011 Reduced.ppt

CALIBRATION AND PERFORMANCE OF THE HAMSR INSTRUMENT DURING

THE NASA GRIP CAMPAIGN

Boon Lim*, Shannon Brown, Richard Denning,

Pekka Kangaslahti, Bjorn Lambrigtsen,

Jordan Tanabe, and Alan Tanner

Jet Propulsion Laboratory*Contact : [email protected]

Outline

• HAMSR Overview

• Genesis and Rapid Intensification Processes (GRIP) Campaign

• Data System

• Thermal Environment

• External target – Stability, Gradients, Reflection

• Nominal Calibration (V0)

• Receiver Temperature Calibration (V1)

• Calibration Comparison (V0 vs V1)

• HAMSR Performance

• Summary

7/29/2011 IGARSS 2011 2

HAMSR Overview• High Altitude MMIC Sounding Radiometer (HAMSR)

• 3 Sounding Bands (55, 118 and 183 GHz)

• 25 total channels

• Oxygen and Water Vapor Bands for Profiling

• Cross-Track Scanner with Ambient/Hot External Calibration Targets

• Product of ESTO (IIP, ACT and AITT)– Entering 15th Year

– Participated in 5 Campaigns

– Integrated on 3 Aircraft

7/29/2011 IGARSS 2011 3

GRIP Campaign

• Genesis and Rapid Intensification Processes Campaign– 5th Coordinated Hurricane Field Campaign Since 1998

– NOAA, NSF and the AF

• From August to September 2010

• DC-8 (9), Global Hawk (4) and WB-57 (2)– Approximately 300 flight hours

• Hurricane Frank (Pacific), Tropical Storm Matthew (Atlantic), Hurricanes Earl and AL-92/Karl (Atlantic)– Global Hawk Stationed at Dryden

– Over 120 Flight Hours for the Global Hawk

– 20 Eye Overpasses Hurricane Karl (~13 Hours)

– Typical flight duration 24 Hours

7/29/2011 IGARSS 2011 4

GRIP Flights

7/29/2011 IGARSS 2011 5

Frank08/28/2010

Earl09/02/2010

Matthew09/23/2010

AL9209/12/2010

Karl09/16/2010

HAMSR Imagery During GRIPHAMSR Imagery During GRIP

Hurricane Earl 2010

Hurricane Matthew Platform Report – Scott Braun

7/29/2011 IGARSS 2011 7

HAMSR GRIP Ground Data SystemHAMSR GRIP Ground Data System

GHOC

HAMSR ground data processor

netC

DF

L1B

file

sJP

L Hur

rican

e Por

tal

HAMSR website

quick look images

RTMM

Commanding

Data downlink

HAMSR software upgraded after GRIP to provide real-time imagery over Iridium

Successfully tested during 2011 WISPAR campaign

Past 30 minutes

Past 60 minutes

Full Dataset

Select HAMSR channel – TB imagery- Full data set, past 30 minutes or past 60 minutes

HAMSR RTMM Display for GRIP

Thermal Environment

• HAMSR Sits in an Unpressurized Pod

• RF Section is Thermally Insulated with Styrofoam

• Temperature Controlled Heaters on the RF Plates– Thermistors Available Across the Instrument

– RF Components (RF/IF LNAs, Mixers), RF Plate Temperatures, Motor, Power Supply, Digital System, Computer, Etc

• Fans for Circulation of Air– On Runway if Temperatures Exceed a Threshold

• At Flight Altitude (~17 km)– Temperature Typically -150C

7/29/2011 IGARSS 2011 10

WISPAR 2011- Thermal Environment

7/29/2011 IGARSS 2011 11

External Target - Stability

• Thermistors Embedded in Targets

• Ambient Target Drifts Freely– Rate of Change 6-7oC/Hour

• Hot Target Held at ~68oC– Oscillation at 120 Second Period, 0.01K<

7/29/2011 IGARSS 2011 12

18:00 00:00 06:00 12:00-20

-15

-10

-5

0

5

10

15

20

Time

Tem

p. 0 C

Ambient Target Temperatures

55 Amb183 Amb

18:00 00:00 06:00 12:0067.6

67.8

68

68.2

68.4

68.6

Time

Tem

p. 0 C

Heated Target Temperatures

55 Hot183 Hot

06:05 06:10 06:15

67.604

67.605

67.606

67.607

67.608

67.609

67.61

67.611

67.612

Time

Tem

p. 0 C

Heated Target Temperatures

183 Hot

External Target - Gradients

• Gradients Across the Target Pixels– Typically Monotonic

– Magnitude Under 0.3K

– Easily Mitigated with Averaging

7/29/2011 IGARSS 2011 13

10 20 30 40 50 60 70 80

339.5

340

340.5

341

341.5

342

Pixel Number

Tem

per

atu

re [K

]

Temperature Variation Across Calibration Target, Channel 20

10 20 30 40 50 60 70 80

339.5

340

340.5

341

341.5

342

Pixel Number

Tem

per

atu

re [K

]


External Target - Reflections

• Standing Waves Setup in the Middle of the Target– Despite Low Return Loss Material (~35 dB)

– Only in Several Frequencies

– Remove Central Pixels

7/29/2011 IGARSS 2011 14

10 20 30 40 50 60 70 80

340

340.5

341

341.5

342

342.5

Pixel Number

Tem

per

atu

re [K

]


10 20 30 40 50 60 70 80

340

340.5

341

341.5

342

342.5

Pixel Number

Tem

per

atu

re [K

]


Initial Processing

• Moving Average of the Hot and Ambient Counts– Period of the Heating Oscillation (~110 Seconds)

• Time ‘Shift’ in Ambient Counts– Account for linear time drifts

• Calculate Per-Scan Gain– Gain = (CHot – CAmb)/(THot – TAmb) [C/K]

• Flag Unusable Pixels (-2)– Insufficient Separation of the Hot and Ambient Targets

– Differential Temperatures on Targets, 5xNEDT

– Differential Gain, Threshold (empirical)

7/29/2011 IGARSS 2011 15

Nominal Processing

• Moving Average of Gain

• Calculate Antenna Temperature– TA = (Ct – CAmb)/Gain + TAmb

• Standard Calibration Stratagy

• Gain Drifts/Jumps Distributed in the Averaging

• Incorrectly Processes ‘Good’ Data

7/29/2011 IGARSS 2011 16

500 1000 1500 2000

21.5

22

22.5

23

23.5

Scan Number (#)

Gai

n [

C/K

]

Smoothed Gain Per Scan, Channel 25, htbV0

500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]

Tb, Unusable Points Removed, Channel 25, htbV0

500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]

Tb, NEDT Points Removed, Channel 25, htbV0

Receiver Temperature Calibration

• Calculate Receiver Temperature– TRx = CAmb/Gain - TAmb

• Smooth Receiver Temperature

• Calculate Gain (from Hot Target)– GHot = CHot/(TRx+CHot)

• Calculate Gain (from Ambient Target)– GAmb = CAmb/(TRx+CAmb)

• Average Gain– Gain = (GHot+GAmb)/2

• Calculate Ta– TA = (Ct – CAmb)/Gain + TAmb

7/29/2011 IGARSS 2011 17

500 1000 1500 2000

21.5

22

22.5

23

23.5

Scan Number (#)

Gai

n [

C/K

]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


Comparison – Gain Smoothing

7/29/2011 IGARSS 2011 18

500 1000 1500 2000

21.5

22

22.5

23

23.5

Scan Number (#)

Gai

n [

C/K

]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


500 1000 1500 2000

21.5

22

22.5

23

23.5

Scan Number (#)

Gai

n [

C/K

]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


Comparison – Spikes

7/29/2011 IGARSS 2011 19

2000 4000 6000 8000 10000 12000 14000 16000 18000

50

52

54

56

58

Scan Number (#)

Gai

n [C

/K]


2000 4000 6000 8000 10000 12000 14000 16000 18000

310

320

330

340

350

360

370

Scan Number (#)

Tem

per

atu

re [

K]


2000 4000 6000 8000 10000 12000 14000 16000 18000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


2000 4000 6000 8000 10000 12000 14000 16000 18000

50

52

54

56

58

Scan Number (#)

Gai

n [

C/K

]


2000 4000 6000 8000 10000 12000 14000 16000 18000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


2000 4000 6000 8000 10000 12000 14000 16000 18000

310

320

330

340

Scan Number (#)

Tem

per

atu

re [

K]


Comparison – Robustness

7/29/2011 IGARSS 2011 20

2000 4000 6000 8000 10000 12000

50

52

54

56

58

60

62

Scan Number (#)

Gai

n [C

/K]


2000 4000 6000 8000 10000 12000300

320

340

360

380

Scan Number (#)

Tem

per

atur

e [K

]


2000 4000 6000 8000 10000 12000

330

335

340

345

350

Scan Number (#)

Tem

per

atur

e [K

]


2000 4000 6000 8000 10000 12000

50

52

54

56

58

60

62

Scan Number (#)

Gai

n [

C/K

]


2000 4000 6000 8000 10000 12000

338

340

342

344

Scan Number (#)

Tem

per

atu

re [

K]


2000 4000 6000 8000 10000 12000337

338

339

340

341

342

343

Scan Number (#)

Tem

per

atu

re [

K]


Flag Marginal Pixels

• Pixels that Exhibit Larger than Expected Noise– Temperature is Over 3.5x NEDT

– Empirical Value for Each Channel

– For End-Product Users

7/29/2011 IGARSS 2011 21

0 5 10 15 20 250

2

4

6

8

10

12

Channel Number [#]

Pix

els

Fla

gg

ed [

%]

Flagging Algorithms Check, htbV0

NEDT FlagUnusable Flag

0 5 10 15 20 250

2

4

6

8

10

12

Channel Number [#]

Pix

els

Fla

gg

ed [

%]



500 1000 1500 2000

21.5

22

22.5

23

23.5

Scan Number (#)

Gai

n [C

/K]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

pera

ture

[K]


500 1000 1500 2000

310

320

330

340

Scan Number (#)

Tem

pera

ture

[K]


Marginal Pixels

7/29/2011 IGARSS 2011 22

2000 4000 6000 8000 10000 12000

50

52

54

56

58

60

62

Scan Number (#)

Gai

n [C

/K]


2000 4000 6000 8000 10000 12000

338

340

342

344

Scan Number (#)

Tem

pera

ture

[K]


2000 4000 6000 8000 10000 12000337

338

339

340

341

342

343

Scan Number (#)

Tem

pera

ture

[K]


Flag Marginal Pixels Second Check

• Receiver Temperature Calibration

• Close to the Theoretical Values for Noise

7/29/2011 IGARSS 2011 23

0 5 10 15 20 250

5

10

15

20

25

30

35

Channel Number [#]

Pix

els

Fla

gg

ed [

%]



0 5 10 15 20 250

5

10

15

20

25

30

35

Channel Number [#]

Pix

els

Fla

gg

ed [

%]



2000 4000 6000 8000 10000 12000

39

40

41

42

Scan Number (#)

Gai

n [C

/K]


2000 4000 6000 8000 10000 12000

339

340

341

342

343

344

Scan Number (#)

Tem

pera

ture

[K]


2000 4000 6000 8000 10000 12000

339

340

341

342

343

344

Scan Number (#)

Tem

pera

ture

[K]


Instrument Performance

• As Derived from the Data– Hurricane Karl

• 55 GHz Performs the Poorest– Legacy Hardware

– Upgrade in Progress (~4dB)

• 118 GHz and 183 GHz Upgraded During AITT

• Performance is as Expected from the Receiver Temperatures

• 99.9% Up-Time– 1 Channel Dropped Out for 3

Hours

7/29/2011 IGARSS 2011 24

Summary

• External Targets Well Characterized

• HAMSR Successfully Participated in GRIP Campaign– Data System Utilized High Bandwidth Link (‘Real-Time’)

– Utility was Immediate in Directing the GH Flight Path

• Calibration Methodology Relies on Stability of Receivers– Front End LNAs vs Entire Gain Chain

• HAMSR Receivers as a System Perform to Measured Receiver Temperatures

• WISPAR Campaign Had Coincident Dropsondes– Absolute Calibration Comparison Pending

• Instrument calibration and characterization (Brown et al., TGRS, in press)

7/29/2011 IGARSS 2011 25

Backup Slides

• HAMSR Timeline

• HAMSR Block Diagram

• External Target Construction

• Pre-Flight Evaluation

• Allan Variance LN2 Stare

• GRIP – Agency Coordination

• Danielle, Earl and Fiona

7/29/2011 IGARSS 2011 26

HAMSR Timeline

7/29/2011 IGARSS 2010=1 27

H S 3

G rip (G H )

N AS A AIT T

N AM M A (D C -8)

T C S P (E R -2)

C AM E X-4 (E R -2)

N AS A IIP

IM AS

1994 1996 1998 2000 2002 2004 2006 2008 2010 2012

HAMSR Block Diagram

7/29/2011 IGARSS 2011 28

ScanningMotor

Encoder

Cal. Targets

Cal. Targets

DichroicPlate

183 GHzRadiometer7 Channels



Digitizers16-Bit

Digitizers16-Bit

FPGAFreeForm Digital IO

Spartan 3E

SPI Bus

CPUAMPRO

Readyboard 620

8-bit ISA

Thermistors40 Channels

16-Bit

RS486 -RS232Converter

NAV420CAGPS and Telemetry

HAMSR

Ethernet

Mylar Apertures

Operator ComputerSystem ConfigurationData Processing

Global Hawk HAMSR Data DownlinkAircraft GPS and Telemetry

External Target - Construction

• Pyramidal Blackbody Calibration Targets– Ambient and ~680C

• Commercial Product with -50dB Return Loss Spec– Heavy Aluminium Coated with a Ferrite Loaded Epoxy Absorbing

Material

– 16x12 cm Area, 4 cm Long Pyramids, 1 cm Apart at Tips

• 4 Thermistors Embedded in Targets at the Tips

• Insulated in Styrofoam– ~35dB Return Loss

7/29/2011 IGARSS 2011 29

Pre-Flight Evaluation – Scan Bias

7/29/2011 IGARSS 2011 30

• Within the field of view, minimal bias in the various channels

• 50 GHz channels: – Bias < 0.5 K for -45o < θ < 45o

• 118/183 GHz channels: – Bias < 0.25 K for -45o < θ < 45o

Allan Variance LN2 Stare

7/29/2011 IGARSS 2011 31

GRIP – Agency Coordination

7/29/2011 IGARSS 2011 32

Danielle, Earl and Fiona

7/29/2011 IGARSS 2011 33

Lim IGARSS2011 Reduced.ppt

Technology

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